System for detecting a liquid and a water filter assembly

ABSTRACT

A system for detecting a liquid, such as liquid water, is provided. The system includes an RFID tag spaced apart from a liquid collection location. The system also includes features for wicking or otherwise transferring liquid from the liquid collection location to the RFID tag. A water filter assembly with features for detecting water leaks is also provided.

FIELD OF THE INVENTION

The present subject matter relates generally to RFID systems.

BACKGROUND OF THE INVENTION

Certain water filter assemblies include a manifold and a filtercartridge. The manifold directs unfiltered water into the filtercartridge and filtered water out of the filter cartridge. The filtercartridge includes a filter medium, such as an activated carbon block, apleated polymer sheet, a spun cord material, or a melt blown material.The filter medium is positioned within the filter cartridge and filterswater passing therethrough.

Over time, the filter medium will lose effectiveness. For example, poresof the filter medium can become clogged or the filter medium can becomesaturated with contaminants. To insure that the filtering medium has notexceeded its filtering capacity, the filtering medium is preferablyreplaced or serviced at regular intervals regardless of its currentperformance. To permit replacement or servicing of the filter medium orthe filter cartridge, the filter cartridge is generally removablymounted to the manifold.

Water leaks can form or develop at an interface or connection betweenthe filter cartridge and the manifold, such as where the filtercartridge mounts to the manifold. As an example, such leaks can developif the water filter assembly is installed incorrectly or is exposed torelatively high water pressures or freezing conditions. Such leaks cannegatively affect operation of the water filter assembly and/or therefrigerator appliance and can cause damage if not prevented. Such leakscan also be difficult to detect. In particular, water filter assembliesare often positioned in relatively remote locations within refrigeratorappliances such that visually monitoring the water filter assemblies forleaks can be difficult or infrequent. Similar problems can makedetecting liquid water and water leaks difficult in other circumstancesand locations as well.

Accordingly, a system or method for detecting liquid, such as liquidwater, would be useful.

BRIEF DESCRIPTION OF THE INVENTION

The present subject matter provides a system for detecting a liquid,such as liquid water. The system includes an RFID tag spaced apart froma liquid collection location. The system also includes features forwicking or otherwise transferring liquid from the liquid collectionlocation to the RFID tag. A water filter assembly with features fordetecting water leaks is also provided. Additional aspects andadvantages of the invention will be set forth in part in the followingdescription, or may be apparent from the description, or may be learnedthrough practice of the invention.

In a first exemplary embodiment, a system for detecting a liquid isprovided. The system includes an RFID tag and an absorbent material. Theabsorbent material extends between a first end portion and a second endportion. The first end portion of the absorbent material is positionedat a liquid collection location. The second end portion of the absorbentmaterial is positioned at the RFID tag. The second end portion of theabsorbent material and the RFID tag are spaced apart from the liquidcollection location.

In a second exemplary embodiment, a water filter assembly is provided.The water filter assembly includes a filter cartridge with a filtermedium disposed therein. The filter cartridge has an outer surface. AnRFID tag is positioned at the outer surface of the filter cartridge. Anabsorbent material is positioned at the outer surface of the filtercartridge. The absorbent material extends between a first end portionand a second end portion. The first end portion of the absorbentmaterial is positioned at a liquid collection location. The second endportion of the absorbent material is positioned over the RFID tag. Thesecond end portion of the absorbent material and the RFID tag are spacedapart from the liquid collection location.

In a third exemplary embodiment, a system for detecting a liquid isprovided. The system includes an RFID tag spaced apart from a liquidcollection location. The system also includes means for wicking liquidfrom the liquid collection location to the RFID tag.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures.

FIG. 1 provides a front, elevation view of a refrigerator applianceaccording to an exemplary embodiment of the present subject matter withrefrigerator doors of the exemplary refrigerator appliance shown in aclosed position.

FIG. 2 provides a front, elevation view of the exemplary refrigeratorappliance of FIG. 1 with refrigerator doors of the exemplaryrefrigerator appliance shown in an open position.

FIG. 3 provides a front, elevation view of a water filter assemblyaccording to an exemplary embodiment of the present subject matter.

FIG. 4 provides a rear, perspective view of the exemplary water filterassembly of FIG. 3.

FIG. 5 provides a front, perspective view of a casing of the exemplarywater filter assembly of FIG. 3.

FIG. 6 provides a perspective view of a filter cartridge of theexemplary water filter assembly of FIG. 3.

FIGS. 7 and 8 provide elevation views of the filter cartridge of FIG. 6.

FIG. 9 provides an elevation view of a system for detecting liquid wateraccording to an exemplary embodiment of the present subject matter.

FIG. 10 provides a plan view of certain components of the exemplarysystem for detecting liquid water of FIG. 9.

FIG. 11 provides an elevation view of a system for detecting liquidwater according to another exemplary embodiment of the present subjectmatter.

FIG. 12 provides an exploded view of the exemplary system for detectingliquid water of FIG. 11.

FIGS. 13, 14 and 15 provide schematic views of certain components of theexemplary system for detecting liquid water of FIG. 11.

FIG. 16 illustrates a method for treating foam according to an exemplaryembodiment of the present subject matter.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

FIG. 1 provides a front, elevation view of a refrigerator appliance 100according to an exemplary embodiment of the present subject matter. FIG.2 provides a front, elevation view of refrigerator appliance 100 withrefrigerator doors 126 and 128 of refrigerator appliance 100 shown in anopen position to reveal a fresh food chamber 122 of refrigeratorappliance 100. Refrigerator appliance 100 defines a vertical directionV, a transverse direction T (FIG. 3), and a lateral direction L. Thevertical direction V, transverse direction T, and lateral direction Lare mutually perpendicular and form an orthogonal direction system.Refrigerator appliance 100 extends between an upper portion 101 and alower portion 102 along the vertical direction V. Refrigerator appliance100 also extends between a first side portion 105 and a second sideportion 106 along the lateral direction L.

Refrigerator appliance 100 includes a cabinet 120 that defines chilledchambers for receipt of food items for storage. In particular,refrigerator appliance 100 defines fresh food chamber 122 at upperportion 101 of refrigerator appliance 100 and a freezer chamber 124arranged below fresh food chamber 122 on the vertical direction V, e.g.,at lower portion 102 of refrigerator appliance 100. As such,refrigerator appliance 100 is generally referred to as a bottom mountrefrigerator appliance. However, using the teachings disclosed herein,one of skill in the art will understand that the present subject mattermay be used with other types of refrigerator appliances (e.g.,side-by-side style or top mount style) or a freezer appliance as well.Consequently, the description set forth herein is for illustrativepurposes only and is not intended to limit the present subject matter toany particular chilled chamber arrangement.

Refrigerator doors 126 and 128 are rotatably hinged to an edge ofcabinet 120 for accessing fresh food chamber 122. In particular, cabinet120 defines an opening 121. Opening 121 of cabinet 120 permits access tofresh food chamber 122 of cabinet 120. Refrigerator doors 126 and 128are positioned at opening 121 of cabinet 120 and permit selective accessto fresh food chamber 122 of cabinet 120 through opening 121 of cabinet120, e.g., by rotating between the open and closed positions. A freezerdoor 130 is arranged below refrigerator doors 126 and 128 for accessingfreezer chamber 124. Freezer door 130 is coupled to a freezer drawer(not shown) slidably mounted within freezer chamber 124.

Refrigerator appliance 100 also includes a dispensing assembly 110 fordispensing water and/or ice. Dispensing assembly 110 includes adispenser 114 positioned on or mounted to an exterior portion ofrefrigerator appliance 100, e.g., on refrigerator door 126. Dispenser114 includes a discharging outlet 134 for accessing ice and water. Asensor 132, such as an ultrasonic sensor, is mounted below dischargingoutlet 134 for operating dispenser 114. In alternative exemplaryembodiments, any suitable actuator may be used to operate dispenser 114.For example, dispenser 114 can include a paddle or button rather thansensor 132. A user interface panel 136 is provided for controlling themode of operation. For example, user interface panel 136 includes awater dispensing button (not labeled) and an ice-dispensing button (notlabeled) for selecting a desired mode of operation such as crushed ornon-crushed ice.

Discharging outlet 134 and sensor 132 are an external part of dispenser114 and are mounted in a dispenser recess 138 defined in an outsidesurface of refrigerator door 126. Dispenser recess 138 is positioned ata predetermined elevation convenient for a user to access ice or waterand enabling the user to access ice without the need to bend-over andwithout the need to access freezer chamber 124. In the exemplaryembodiment, dispenser recess 138 is positioned at a level thatapproximates the chest level of a user.

Turning now to FIG. 2, certain components of dispensing assembly 110 areillustrated. Dispensing assembly 110 includes an insulated housing 142mounted within fresh food chamber 122. Due to the insulation whichencloses insulated housing 142, the temperature within insulated housing142 can be maintained at levels different from the ambient temperaturein the surrounding fresh food chamber 122.

Insulated housing 142 is constructed and arranged to operate at atemperature that facilitates producing and storing ice. Moreparticularly, insulated housing 142 contains an ice maker (not shown)for creating ice and feeding the same to a container 160 that is mountedon refrigerator door 126. As illustrated in FIG. 2, container 160 isplaced at a vertical position on refrigerator door 126 that will allowfor the receipt of ice from a discharge opening 162 located along abottom edge 164 of insulated housing 142. As refrigerator door 126 isclosed or opened, container 160 is moved in and out of position underinsulated housing 142.

Refrigerator appliance 100 also includes a water filter assembly 170.Water filter assembly 170 can filter water from a water supply (notshown), such as a municipal water source or a well. Water filterassembly 170 can remove contaminants and other undesirable substancesfrom water passing therethrough. As will be understood by those skilledin the art and as used herein, the term “water” includes purified waterand solutions or mixtures containing water and, e.g., elements (such ascalcium, chlorine, and fluorine), salts, bacteria, nitrates, organics,and other chemical compounds or substances.

Water filter assembly 170 is mounted to cabinet 120. In particular,water filter assembly 170 is mounted to refrigerator door 126 in theexemplary embodiment shown in FIG. 2. However, it should be understoodthat water filter assembly 170 can be positioned at any other suitablelocation within refrigerator appliance 100 in alternative exemplaryembodiments. For example, water filter assembly 170 may be mounted torefrigerator door 128, to cabinet 120 within fresh food chamber 122, orto cabinet 120 below freezer chamber 124 in alternative exemplaryembodiments. Thus, the position of water filter assembly 170 shown inFIG. 2 is not intended to limit the present subject matter in any aspectand is provided by way of example only.

Refrigerator appliance 100 also includes a valve 172 as schematicallyshown in FIG. 2. Valve 172 is configured for regulating a flow of waterto water filter assembly 170. In particular, valve 172 can selectivelyshift between a closed position and an open position. Valve 172 permitsthe flow of water to water filter assembly 170 in the open position.Thus, with valve 172 in the open position, water for filtering issupplied to water filter assembly 170. Conversely, valve 172 obstructsor blocks the flow of water to water filter assembly 170 in the closedposition. Thus, with valve 172 in the closed position, water forfiltering is not supplied to water filter assembly 170 or is supplied towater filter assembly 170 in an insubstantial volume. In such a manner,valve 172 can regulate the flow of water to water filter assembly 170 byshifting between the open and closed positions.

FIG. 3 provides a front elevation view of a water filter assembly 200according to an exemplary embodiment of the present subject matter. FIG.4 provides a rear perspective view of water filter assembly 200. Waterfilter assembly 200 can be used in any suitable appliance. For example,water filter assembly 200 may be used in refrigerator appliance 100(FIG. 2) as water filter assembly 170 (FIG. 2). As discussed in greaterdetail below, water filter assembly 200 is configured for filteringwater passing therethrough. In such a manner, water filter assembly 200can provide filtered water to various components of refrigeratorappliance 100, such as dispensing assembly 110 or the ice maker (notshown) within insulated housing 142. Water filter assembly 200 may alsobe used to filter water at any other suitable location. For example,water filter assembly 200 may be utilized as a point-of-entry waterfilter for a building or residence. As another example, water filterassembly 200 may be utilized as a point-of-use water filter for afaucet, a water fountain, etc.

As may be seen in FIG. 3, water filter assembly 200 includes a housingor casing 210. Casing 210 extends between a top portion 212 and a bottomportion 214, e.g., along the vertical direction V. As an example, casing210 can be mounted to any suitable portion of refrigerator appliance 100in order to mount water filter assembly 200 to refrigerator appliance100. For example, casing 210 may be mounted to refrigerator door 126 orcabinet 120. In particular, casing 210 may be encased within or engageinsulating foam (not shown) of cabinet 120 to mount water filterassembly 200 to refrigerator appliance 100. As another example, casing210 may be mounted to a wall of building or residence, e.g., when waterfilter assembly 200 is utilized as a point-of-entry water filter.

Water filter assembly 200 also includes a manifold 220. Manifold 220 ismounted to casing 210. Manifold 220 is configured for receivingunfiltered water and directing filtered water out of water filterassembly 200. In particular, manifold 220 includes an inlet conduit 221that defines an inlet 222. Inlet 222 receives unfiltered water, e.g.,from a water source (not shown) such as a municipal water supply or awell. Manifold 220 also includes an outlet conduit 223 that defines anoutlet 224. Outlet 224 directs filtered water out of water filterassembly 200. Thus, manifold 220 receives unfiltered water at inlet 222.Such unfiltered water passes through water filter assembly 200 and exitsmanifold 220 at outlet 224 as filtered water.

As shown in FIG. 3, water filter assembly 200 includes a filter canisteror filter cartridge 230 for filtering unfiltered water received at inlet222 of manifold 220. Thus, filter cartridge 230 filters water passingthrough water filter assembly 200. Filter cartridge 230 extends betweena first end portion 232 and a second end portion 234, e.g., along thelateral direction L. A connection 236 of filter cartridge 230 ispositioned at or proximate first end portion 232 of filter cartridge230. Connection 236 of filter cartridge 230 is configured for engagingmanifold 220, e.g., in order to removably mount filter cartridge 230 tomanifold 220.

Connection 236 of filter cartridge 230 also places filter cartridge 230in fluid communication with manifold 220 when filter cartridge 230 ismounted to manifold 220. Thus, filter cartridge 230 can receiveunfiltered water from inlet 222 of manifold 220 at connection 236 anddirect such unfiltered water into a chamber 231 when filter cartridge230 is mounted to manifold 220. Water within chamber 231 can passthrough a filtering medium 233 positioned within chamber 231 and canexit chamber 231 as filtered water. In particular, connection 236 offilter cartridge 230 can direct filtered water out of chamber 231 tooutlet 224 of manifold 220 when filter cartridge 230 is mounted tomanifold 220. In such a manner, filtering medium 233 of filter cartridge230 can filter a flow of water through water filter assembly 200. Suchfiltering can improve taste and/or safety of water.

Filtering medium 233 can include any suitable mechanism for filteringwater within water filter assembly 200. For example, filtering medium233 may include an activated carbon block, a reverse osmosis membrane, apleated polymer or cellulose sheet, or a melt blown or spun cord medium.As used herein, the term “unfiltered” describes water that is notfiltered relative to filtering medium 233. However, as will beunderstood by those skilled in the art, water filter assembly 200 mayinclude additional filters that filter water entering chamber 231. Thus,“unfiltered” may be filtered relative to other filters but not filteringmedium 233.

As will be understood by those skilled in the art, filtering medium 233of filter cartridge 230 can lose efficacy over time. Thus, a user canreplace filter cartridge and/or filtering medium 233 of filter cartridge230 at regular intervals or after a certain volume of water has passedthrough filter cartridge 230. To replace filter cartridge 230 and/orfiltering medium 233 of filter cartridge 230, the user can remove ordisconnect filter cartridge 230 from manifold 220 and insert or mount anew filter cartridge 230 or filtering medium 233 of filter cartridge230.

Water filter assembly 200 can be exposed to a variety of conditionswithin that can negatively affect performance of water filter assembly200. For example, high water pressure at inlet 222 of manifold 220and/or connection 236 of filter cartridge 230 or exposing water filterassembly 200 to freezing conditions can negatively affect performance ofwater filter assembly 200. Such conditions can cause water filterassembly 200 to leak, e.g., at connection 236 of filter cartridge 230.Such conditions can also cause water filter assembly 200 to deform orcrack. As discussed in greater detail below, water filter assembly 200includes features for detecting such malfunctions of water filterassembly 200.

FIG. 6 provides a perspective view of filter cartridge 230 of waterfilter assembly 200. FIGS. 7 and 8 provide elevation views of filtercartridge 230. As may be seen in FIGS. 6, 7 and 8, water filter assembly200 includes a system 240 for detecting liquid water. It should beunderstood that system 240 can be used to detect liquid water and/orwater leaks in any other suitable setup or arrangement in alternativeexemplary embodiments. Thus, while described in the context of waterfilter assembly 200, system 240 may be used to detect water leaks fromany suitable container, vessel, pipe or conduit or to detect liquidwater in the container, vessel, pipe or conduit or on the surface inalternative exemplary embodiments.

As may be seen in FIG. 6, system 240 includes a radio frequencyidentification reader or RFID reader 242 (shown schematically). System240 also includes a radio frequency identification tag or RFID tag 244.RFID reader 242 is configured for receiving a signal from RFID tag 244.Thus, RFID reader 242 and RFID tag 244 can be in signal communicationwith each other as will be understood by those skilled in the art. Forexample, RFID reader 242 and RFID tag 244 may be in signal communicationwith each other as described in U.S. patent application Ser. No.14/052,847 entitled “A Refrigerator Appliance and A Method ForMonitoring A Water Filter Assembly Within The Same” and/or U.S. patentapplication Ser. No. 14/052,837 entitled “A System And A Method ForDetecting Liquid Water,” both of which are incorporated by referenceherein in their entireties.

In certain exemplary embodiments, RFID tag 244 is a passive RFID tag.Thus, RFID reader 242 can receive a radio signal from RFID tag 244 inresponse to a query or request signal from RFID reader 242. Inparticular, RFID tag 244 can generate or transmit the response radiosignal utilizing energy transmitted, e.g., wirelessly, to RFID tag 244from RFID reader 242 via the query or request signal from RFID reader242. Thus, RFID tag 244 need not include a battery or other power sourcein order to generate or transmit the response radio signal. In otherexemplary embodiments, RFID tag 244 is an active RFID tag and includes abattery or is connected to a suitable power source. Thus, RFID tag 244can continuously or intermittently generate or transmit a signal thatRFID reader 242 can receive. As will be understood by those skilled inthe art, RFID reader 242 and RFID tag 244 can have any other suitablesetup or configuration for placing RFID reader 242 and RFID tag 244 insignal communication with each other. Thus, RFID reader 242 may bepassive or active, and RFID tag 244 may be passive or active dependingupon the desired setup of system 240.

As will be understood by those skilled in the art, signal communicationbetween RFID reader 242 and RFID tag 244 is affected by a variety offactors. For example, signal communication between RFID reader 242 andRFID tag 244 can be limited or terminated if a gap between RFID reader242 and RFID tag 244 is increased. RFID reader 242 and RFID tag 244 canalso be tuned such that signal communication between RFID reader 242 andRFID tag 244 is established with a particular transmission medium, suchas air, disposed between RFID reader 242 and RFID tag 244, e.g., withinthe gap between RFID reader 242 and RFID tag 244. Thus, the signalcommunication between RFID reader 242 and RFID tag 244 can be disruptedor terminated if the transmission medium changes and another material ispositioned between RFID reader 242 and RFID tag 244. For example, ifwater is positioned between RFID reader 242 and RFID tag 244, the signalcommunication between RFID reader 242 and RFID tag 244 can be terminatedor disrupted. In particular, liquid water can absorb radio waves andthereby terminate or disrupt signal communication between RFID reader242 and RFID tag 244. Liquid water can also affect transmission andreception of radio waves by antennas of RFID reader 242 and/or RFID tag244. As discussed in greater detail below, when signal communicationbetween RFID reader 242 and RFID tag 244 is disrupted, lost orterminated, it can be inferred that liquid water is disposed betweenRFID reader 242 and RFID tag 244 (e.g., that liquid water is disposedwithin the gap between RFID reader 242 and RFID tag 244). For example,when signal communication between RFID reader 242 and RFID tag 244 isinterrupted, it can be inferred that water filter assembly 200 isleaking or otherwise malfunctioning.

It should be understood that system 240 can be used to detect liquidwater and/or water leaks in any other suitable setup or arrangement.Thus, RFID tag 244 need not be mounted to filter cartridge 230 inalternative exemplary embodiments. For example, RFID tag 244 may bemounted to any other suitable container, vessel, pipe, conduit, surface,etc. In such a manner, system 240 may be used to detect water leaks fromthe container, vessel, pipe or conduit or to detect liquid water in thecontainer, vessel, pipe or conduit or on the surface. In addition,system 240 may also be arranged or configured to detect any othersuitable liquid in alternative exemplary embodiments.

Water filter assembly 200 also includes features for collecting waterleaking from water filter assembly 200. FIG. 5 provides a frontperspective view of casing 210 of water filter assembly 200. As may beseen in FIG. 5, water filter assembly 200 includes a liquid collector250. Liquid collector 250 defines a collection volume 252. As anexample, liquid collector 250 may include a side wall 254 that ismounted to casing 210 and extends away from casing 210. In particular,side wall 254 may be position at bottom portion 214 of casing 210 andmay extend from casing 210 upwardly, e.g., along the vertical directionV, towards filter cartridge 230. Thus, as shown in FIG. 3, liquidcollector 250 may be positioned (e.g., directly) below filter cartridge230, e.g., along the vertical direction V. An absorptive material (notshown), such as cellulose sponge, may be positioned within collectionvolume 252 of liquid collector 250 in order to assist with collectionwater therein. In certain exemplary embodiments, side wall 254 need notbe included if liquid collector 250 includes the absorptive material atcollection volume 252 of liquid collector 250.

Liquid collector 250 may be mounted to casing 210, e.g., at bottomportion 214 of casing 210. In particular, liquid collector 250 may becontinuous with or integrally mounted to casing 210. Thus, as anexample, casing 210 and liquid collector 250 may be constructed of orwith a single, continuous piece of molded plastic. In particular, sidewall 254 of liquid collector 250 may be continuous with or integrallymounted to casing 210.

Liquid collector 250 is positioned for collecting liquid leaking fromfilter cartridge 230. As an example, liquid may leak from a crack infilter cartridge 230. Such liquid may flow on an outer surface 238 offilter cartridge 230, e.g., downwardly along the vertical direction V.By being positioned below filter cartridge 230, e.g., along the verticaldirection V, such liquid may then flow into collection volume 252 ofliquid collector 250 and fill or pool within collection volume 252.

Liquid collector 250 is also positioned for collecting liquid leakingfrom connection 236 of filter cartridge 230 and manifold 220. As anexample, liquid collector 250, e.g., collection volume 252 of liquidcollector 250, may be positioned (e.g., directly) below connection 236of filter cartridge 230 and manifold 220, e.g., along the verticaldirection V. Thus, liquid may leak from connection 236 of filtercartridge 230 and manifold 220 and flow into collection volume 252 ofliquid collector 250 where the liquid can fill or pool within collectionvolume 252. As discussed in greater detail below, by collecting liquidwithin collection volume 252, detection of liquid leaking from waterfilter assembly 200 may be improved.

Turning back to FIG. 6, system 240 also include features for wickingliquid from a liquid collection location, such as collection volume 252of liquid collector 250, to RFID tag 244. Thus, RFID tag 244 may detectliquid water and/or water leaks despite RFID tag 244 being spaced apartor remotely located from the liquid collection location. As an example,RFID tag 244 may be positioned above collection volume 252 of liquidcollector 250, e.g., along the vertical direction V. As discussed above,collection volume 252 of liquid collector 250 can receive liquid leakingfrom filter cartridge 230 and/or connection 236 of filter cartridge 230and manifold 220. Liquid within collection volume 252 of liquidcollector 250 can be wicked upwardly to RFID tag 244 in order to disruptor terminate the signal communication between RFID reader 242 and RFIDtag 244.

As may be seen in FIG. 6, system 240 includes a hydroscopic or absorbentmaterial 260. Absorbent material 260 extends between a first end portion262 and a second end portion 264, e.g., along the vertical direction V.First and second end portions 262 and 264 of absorbent material 260 arespaced apart from each other, e.g., along the vertical direction V.Thus, first and second end portions 262 and 264 of absorbent material260 may be positioned at separate locations, and absorbent material 260may wick or otherwise transfer liquid between the first and second endportions 262 and 264 of absorbent material 260. As an example, first endportion 262 of absorbent material 260 may be positioned at a liquidcollection location, such as collection volume 252 of liquid collector250 (FIG. 5). Conversely, second end portion 264 of absorbent material260 may be positioned at or over RFID tag 244. Thus, second end portion264 of absorbent material 260 and RFID tag 244 may be spaced apart fromthe liquid collection location, and absorbent material 260 may wick orotherwise transfer liquid from the liquid collection location to theRFID tag 244. In such a manner, absorbent material 260 may assist withpermitting RFID tag 244 to be positioned remotely relative to the liquidcollection location, and, thereby, permit detection of liquid withsystem 240 at locations where RFID tag 244 cannot be directlypositioned. However, it should be understood that RFID tag 244 may bepositioned directly within collection volume 252 of liquid collector 250in alternative exemplary embodiments. In addition, RFID tag 244 may bepositioned at any other suitable location on outer surface 238 of filtercartridge 230 in alternative exemplary embodiments, e.g., when filtercartridge 230 is vertically oriented and liquid collector 250 is notincluded.

Absorbent material 260 may be any suitable absorbent material. Forexample, absorbent material 260 may be or include cellulose foam, paperor synthetic foam. In addition, an electrolyte may be disposed withinabsorbent material 260. Thus, absorbent material 260 may be doped withthe electrolyte. Any suitable electrolyte may be disposed withinabsorbent material 260. For example, a water soluble electrolyte, suchas sodium bicarbonate, sodium chloride or potassium sulfate, may bedisposed within absorbent material 260. It should be understood thatabsorbent material 260 need not be a single, continuous piece ofmaterial. Thus, e.g., absorbent material 260 may be constructed of orwith a plurality of absorbent pieces positioned adjacent each other.

As discussed above, RFID tag 244 may be inoperable or signalcommunication between RFID tag 244 and RFID reader 242 may bediminished, e.g., if liquid is disposed within absorbent material 260 atsecond end portion 264 of absorbent material 260. For example, liquidwithin absorbent material 260 at second end portion 264 of absorbentmaterial 260 may short out the antenna of RFID tag 244. As anotherexample, a resistance of absorbent material 260 can decrease (e.g., dueto the electrolyte therein dissolving) thereby putting a load on theantenna of RFID tag 244. As the resistance drops, the load can increaseuntil the load drains sufficient power from RFID tag 244 such that RFIDtag 244 is disabled or deactivated and signal communication between RFIDreader 242 and RFID tag 244 is disrupted or terminated. Further, whenabsorbent material 260 is wet, e.g., such that the electrolyte withinabsorbent material 260 is dissolved, the capacitance of the antenna ofRFID tag 244 may be a second capacitance value. The second capacitancevalue can be selected such that the signal communication between RFIDreader 242 and RFID tag 244 is disrupted or terminated due to theassociated change in the resonant frequency of RFID tag 244.

As may be seen in FIG. 6, system 240 also includes an impermeablematerial 270. Impermeable material 270 may be positioned over RFID tag244 and/or absorbent material 260. As an example, impermeable material270 may be mounted to filter cartridge 230 at outer surface 238 offilter cartridge 230. Thus, impermeable material 270 may assist withmounting or securing RFID tag 244 and/or absorbent material 260 tofilter cartridge 230.

Impermeable material 270 defines a passage 272 therethrough. Passage 272permits liquid to flow through impermeable material 270, e.g., toabsorbent material 260 disposed below impermeable material 270. As anexample, passage 272 of impermeable material 270 may be positioned at oradjacent the liquid collection location, and first end portion 262 ofabsorbent material 260 may be positioned at or adjacent passage 272 ofimpermeable material 270. Thus, impermeable material 270 may bepositioned between the liquid collection location and absorbent material260, and passage 272 may permit liquid to flow through impermeablematerial 270 to absorbent material 260. In particular, absorbentmaterial 260 may be configured or positioned for wicking liquid frompassage 272 of impermeable material 270 at first end portion 262 ofabsorbent material 260 to second end portion 264 of absorbent material260 and RFID tag 244. Thus, impermeable material 270 may assist withhindering or preventing absorbent material 260 from collecting orabsorbing liquid from locations other than the liquid collectionlocation.

FIG. 9 provides an elevation view of a system 300 for detecting liquidwater according to an exemplary embodiment of the present subjectmatter. FIG. 10 provides a plan view of certain components of system300. In FIG. 9, system 300 is shown with filter cartridge 230. It shouldbe understood that system 300 may be used to detect liquid water and/orwater leaks in any other suitable setup or arrangement in alternativeexemplary embodiments. Thus, while described in the context of filtercartridge 230, system 300 may be used to detect water leaks from anysuitable container, vessel, pipe or conduit or to detect liquid water inthe container, vessel, pipe or conduit or on the surface in alternativeexemplary embodiments. In addition, system 300 may also be arranged orconfigured to detect any other suitable liquid in alternative exemplaryembodiments.

System 300 includes similar components as system 240 (FIG. 6) describedabove. Thus, system 300 may function in a similar manner to detectliquid. As may be seen in FIGS. 9 and 10, system 300 includes an RFIDtag 310, a hydroscopic or absorbent layer or material 320, and animpermeable layer or material 330. Absorbent material 320 extendsbetween a passage 332 of impermeable material 330 and RFID tag 310beneath impermeable material 330. Thus, absorbent material 320 may wickliquid from passage 332 of impermeable material 330 to RFID tag 310.

Impermeable material 330 may be constructed of or with any suitableimpermeable material 330. For example, impermeable material 330 may beconstructed of or with a material that is impermeable to the liquidbeing detected by system 300. In certain exemplary embodiments,impermeable material 330 may be a, e.g., flexible, plastic film orlayer. In addition, impermeable material 330 may further include anadhesive, such as a pressure sensitive adhesive, disposed on the plasticfilm. Thus, impermeable material 330 may act as a sticker or tape toassist with mounting absorbent material 320 and RFID tag 310 to asurface. In such a manner, system 300 may be easily mountable at oradjacent a liquid collection location.

FIG. 11 provides an elevation view of a system 400 for detecting liquidwater according to another exemplary embodiment of the present subjectmatter. FIG. 12 provides an exploded view of system 400. In FIGS. 11 and12, system 400 is shown with filter cartridge 230. It should beunderstood that system 400 may be used to detect liquid water and/orwater leaks in any other suitable setup or arrangement in alternativeexemplary embodiments. Thus, while described in the context of filtercartridge 230, system 400 may be used to detect water leaks from anysuitable container, vessel, pipe or conduit or to detect liquid water inthe container, vessel, pipe or conduit or on the surface in alternativeexemplary embodiments. In addition, system 400 may also be arranged orconfigured to detect any other suitable liquid in alternative exemplaryembodiments.

System 400 includes similar components as system 240 (FIG. 6) describedabove. Thus, system 400 may function in a similar manner to detectliquid. As may be seen in FIGS. 11 and 12, system 400 includes an RFIDtag 410, a hydroscopic or absorbent material 420, and an impermeablematerial 430. Absorbent material 420 extends between a first end portion424 and a second end portion 426. First end portion 424 of absorbentmaterial 420 is positioned at, e.g., directly beneath, passages 432 ofimpermeable material 430, and second end portion 426 of absorbentmaterial 420 is positioned over RFID tag 410. Thus, absorbent material420 may extend beneath impermeable material 430 between passages 432 andRFID tag 410. In addition, absorbent material 420 may wick liquid frompassages 432 of impermeable material 430 to RFID tag 410. In system 400,absorbent material 420 is constructed of or with a foam material, suchas cellulose foam or synthetic foam. System 400 also includes featuresfor hindering, e.g., mechanical, compression of absorbent material 420,as discussed in greater detail below.

FIGS. 13, 14 and 15 provide schematic views of certain components ofsystem 400. In FIG. 13, absorbent material 420 is dry such that pores422 of absorbent material 420 contain little or no liquid therein. InFIG. 14, absorbent material 420 is damp such that pores 422 of absorbentmaterial 420 contain liquid therein. Absorbent material 420 may be damp,e.g., when absorbent material 420 is exposed to condensation orpositioned in a humid environment. In FIG. 15, absorbent material 420 issaturated such that pores 422 of absorbent material 420 are filled withliquid. Absorbent material 420 may be saturated, e.g., when absorbentmaterial 420 is exposed to or contacts a pool of liquid.

In system 400, absorbent material 420 contains an electrolyte, such assodium bicarbonate, sodium chloride or potassium sulfate, therein. Theelectrolyte within absorbent material 420 may not dissolve or may notcompletely dissolve when absorbent material 420 is damp as shown in FIG.14. Conversely, the electrolyte within absorbent material 420 may, e.g.,completely, dissolve and ionize when absorbent material 420 is saturatedas shown in FIG. 15. Thus, a conductivity of absorbent material 420 mayincrease when absorbent material 420 is saturated thereby putting a loadon the antenna of RFID tag 410. As the conductivity increases, the loadcan increase until the load drains sufficient power from RFID tag 410such that RFID tag 410 is disabled or deactivated and signalcommunication between an associated RFID reader and RFID tag 410 isdisrupted or terminated.

As will be understood by those skilled in the art, compressing absorbentmaterial 420 decreases a size of pores 422 and decreases a volume ofliquid required to saturate absorbent material 420. Thus, a sensitivityof absorbent material 420 may be increased by compressing absorbentmaterial 420. However, system 400 may be disposed in a damp environment,such as an area with high condensation or high humidity. To avoidtriggering system 400 with such condensation or humidity, system 400also includes features for hindering compression of absorbent material420, e.g., and thereby decrease a sensitivity of system 400.

Turning back to FIGS. 11 and 12, impermeable material 430 includes arigid casing 436. Rigid casing 436 is positioned over absorbent material420 and RFID tag 410. As an example, rigid casing 436 may be mounted tofilter cartridge 230 at outer surface 238 of filter cartridge 230. Rigidcasing 436 may be constructed of or with any suitable rigid material330. For example, rigid casing 436 may be constructed of or with a rigidmaterial that is impermeable to the liquid being detected by system 400.In certain exemplary embodiments, rigid casing 436 may be a rigidplastic, such as polystyrene, polyethylene, polyvinyl chloride,polypropylene, etc.

As may be seen in FIGS. 11 and 12, rigid casing 436 defines passages432. Rigid casing 436 also defines at least one vent opening 434. Ventopening 434 is positioned, e.g., directly, over second end portion 426of absorbent material 420 and/or RFID tag 410. Vent opening 434 maypermit or facilitate evaporation of liquid in absorbent material 420 atsecond end portion 426 of absorbent material 420. It should beunderstood that rigid casing 436 need not include vent opening 434 inalternative exemplary embodiments.

Turning now to FIGS. 13, 14 and 15, rigid casing 436 defines an interiorvolume 438. Absorbent material 420 may be positioned or disposed withininterior volume 438 of rigid casing 436, e.g., such that absorbentmaterial 420 is encased or enclosed within rigid casing 436. In such amanner, rigid casing 436 may hinder or prevent compression of absorbentmaterial 420.

System 400 may also include a liquid or water permeable layer ormaterial 440 positioned between RFID tag 410 and absorbent material 420,e.g., within interior volume 438 of rigid casing 436. Water permeablematerial 440 may be any suitable water permeable material. For example,water permeable material 440 may be a plastic mesh, such as apolypropylene mesh, in certain exemplary embodiments. Water permeablematerial 440 spaces RFID tag 410 and absorbent material 420, e.g., whilepermitting liquid to pass from absorbent material 420 to RFID tag 410through water permeable material 440. Such spacing may assist withhindering or preventing triggering of system 400 in damp environments,e.g., due to condensation or humidity. Thus, water permeable material440 may assist with decreasing a sensitivity of system 400.

As may be seen in FIGS. 13, 14 and 15, absorbent material 420 is spacedapart from RFID tag 410 by a gap G, e.g., along the lateral direction Lor the transverse direction T. The gap G may be any suitable size. Forexample, gap G may be less than about three millimeters, less than abouttwo millimeters or less than about a millimeter. Thus, absorbentmaterial 420 may be spaced apart from RFID tag 410 by less than aboutthree millimeters, less than about two millimeters, less than about amillimeter, etc., within interior volume 438 of rigid casing 436.

Water permeable material 440 may be positioned within and extend acrossthe gap G. Thus, water permeable material 440 may extend betweenabsorbent material 420 and RFID tag 410 within the gap G. Rigid casing436 also includes at least one spacer 442 that extends across the gap Gto RFID tag 410. In alternative exemplary embodiments, spacer 442 mayextend through interior volume 438 of rigid casing 436 across the gap Gto RFID tag 410. Spacer 442 may be integral or continuous with rigidcasing 436. Thus, as an example, spacer 442 and rigid casing 436 may beconstructed of a single piece of molded plastic. Spacer 442 may be usedin addition to water permeable material 440 as shown in FIGS. 13, 14 and15 or without water permeable material 440. In alternative exemplaryembodiments, any suitable combination of water permeable material 440and spacer 442 may be used to space absorbent material 420 from RFID tag410.

FIG. 16 illustrates a method 500 for treating foam according to anexemplary embodiment of the present subject matter. Method 500 may beused to treat any suitable foam. For example, method 500 may be used totreat absorbent material 260 of system 240 (FIG. 6), absorbent material320 of system 300 (FIG. 9) and/or absorbent material 420 of system 400(FIG. 11). Utilizing method 500, a thickness of such absorbent materialsmay be reduced to a suitable thickness for use in the systems.

At step 510, a foam blank is provided. The foam blank may be anysuitable foam. For example, the foam blank may be cellulose foam orsynthetic foam. In addition, the foam blank may be cut to size at step510. In alternative exemplary embodiments, the foam blank may be cut tosize at any other suitable time.

At step 520, the foam blank is treated with an electrolyte. Thus, anelectrolyte may be disposed within the foam blank at step 520. As anexample, foam blank may be exposed to an electrolyte solution at step520 by spraying the foam blank with the electrolyte solution or soakingthe foam blank in the electrolyte solution. The electrolyte may be anysuitable electrolyte at step 520. As an example, the electrolyte mayhave a low hygroscopicity. As another example, the electrolyte mayinclude a non-deliquescent electrolyte such that the electrolyte is notdeliquescent. Thus, the electrolyte may not absorb water out of theatmosphere. As a particular example, the electrolyte disposed within thefoam blank at step 520 may include sodium bicarbonate, sodium chlorideand/or potassium sulfate.

At step 530, the foam blank is compressed. In particular, the foam blankmay be compressed such that a thickness of the foam blank is reduced astep 530. For example, the foam blank may have a first surface and asecond surface positioned opposite each other on the foam blank, and thefoam blank may be compressed at step 530 such that the first and secondsurfaces of the foam blank are spaced apart from each other by less thanabout three hundredths of an inch during step 530.

At step 540, the foam blank is dried, e.g., while the foam blank iscompressed. As an example, the foam blank may be heated to assist withdrying the foam blank at step 540. In particular, the foam blank may beheated in a hot press such that the first and second surfaces of thecellulose foam are spaced apart from each other by less than about threehundredths of an inch during step 540.

In such a manner, a foam blank, such as a piece of cellulose foam, maybe treated with an electrolyte and compressed in order to reduce thethickness of the foam blank. In particular, the thickness of the foamblank may be greater than about three hundredths of an inch (e.g.,greater than about six hundredths of an inch) before step 530, and thethickness of the foam blank may be less than about three hundredths ofan inch after step 540.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A water filter assembly for filtering a liquid,comprising: a filter cartridge with a filter medium disposed therein,the filter cartridge having an outer surface, the filter medium forremoving contaminants from the liquid; a radio frequency identification,RFID, tag positioned at the outer surface of the filter cartridge,wherein the RFID tag is configured to detect liquid leaking; anabsorbent material positioned at the outer surface of the filtercartridge, the absorbent material extending longitudinally between afirst end portion and a second end portion, the first end portion of theabsorbent material positioned at a liquid collection location, thesecond end portion of the absorbent material positioned over the RFIDtag, the second end portion of the absorbent material and the RFID tagspaced apart from the liquid collection location on the outer surface ofthe filter cartridge; and a water impermeable material positioned overthe RFID tag and the absorbent material on the outer surface of thefilter cartridge, the water impermeable material mounted to the othersurface of the filter cartridge such that the water impermeable materialoverlays the RFID tag and the absorbent material on the outer surface ofthe filter cartridge and such that the RFID tag and the absorbentmaterial are encased between the water impermeable material and theouter surface of the filter cartridge, the water impermeable materialdefining a passage extending through the water impermeable materialbetween the liquid collection location and the absorbent material suchthat the liquid collection location is in fluid communication with theabsorbent material at the first end portion of the absorbent material,the first end portion of the absorbent material being positioned at thepassage of the water impermeable material, wherein the water impermeablematerial covers the absorbent material on the outer surface of thefilter cartridge between the first and second end portions of theabsorbent material, the absorbent material is configured for wickingliquid leaking beneath the water impermeable material from the passageof the water impermeable material at the first end portion of theabsorbent material to the second end portion of the absorbent materialand the RFID tag, and wherein the water impermeable material preventsthe absorbent material from absorbing liquid leaking from the filtercartridge at locations other than the passage of the water impermeablematerial.
 2. The water filter assembly of claim 1, wherein the absorbentmaterial comprises cellulose foam, paper or synthetic foam.
 3. The waterfilter assembly of claim 1, wherein the water impermeable materialcomprises a plastic film.
 4. The water filter assembly of claim 3,wherein the water impermeable material further comprises an adhesivemounting the plastic film to the filter cartridge at the outer surfaceof the filter cartridge.
 5. The water filter assembly of claim 1,wherein the water impermeable material further defines a vent opening,the vent opening positioned over the second end portion of the absorbentmaterial and the RFID tag.
 6. The water filter assembly of claim 1,wherein the second end portion of the absorbent material is positionedabove the first end portion of the absorbent material.
 7. The waterfilter assembly of claim 1, wherein the RFID tag is inoperable or signalcommunication between the RFID tag and an RFID reader is diminished ifliquid is disposed within the absorbent material at the second endportion of the absorbent material.
 8. The water filter assembly of claim1, wherein the water impermeable material comprises a plastic filmadhered to the outer surface of the filter cartridge and the absorbentmaterial comprises an electrolyte doped paper, the water impermeablematerial preventing the absorbent material from absorbing the liquidfrom locations other than the liquid collection location.